Protesters are directed to a bus for transport after getting arrested after protesting the acquittal of Cleveland police officer Michael Brelo Saturday in Cleveland. The acquittal came at a time of nationwide tension among police and black citizens punctuated by protests over the deaths of black suspects at the hands of white officers — and following a determination by the U.S. Department of Justice that Cleveland police had a history of using excessive force and violating civil rights.

CLEVELAND >> The streets returned to calm Sunday after police arrested dozens of demonstrators overnight when protests grew increasingly aggressive in the wake of a patrolman’s acquittal in the deaths of two unarmed black suspects.

In total, 71 people were arrested, including several who turned their anger toward bystanders in downtown Cleveland, Police Chief Calvin Williams said. Someone picked up a restaurant sign and hit a patron in the head, and other protesters used pepper spray on passers-by and restaurant patrons sitting at outdoor cafes.

But Mayor Frank Jackson thanked the vast majority of protesters who remained peaceful and respectful as they voiced their frustration with Saturday’s verdict.

Officer Michael Brelo, 31, faces administrative charges while remaining suspended without pay after he was found not guilty on two counts of voluntary manslaughter, but he no longer faces the prospect of prison. The anxious city now awaits a decision on criminal charges against a white officer in the fatal shooting of a black 12-year-old boy with a pellet gun.

Brelo and 12 other officers fired 137 shots at a car with Timothy Russell and Malissa Williams inside it on Nov. 29, 2012. The shooting occurred at the end of a 22-mile chase involving more than 100 Cleveland police officers and 60 cruisers after Russell’s Chevy Malibu backfired while speeding past police headquarters. During the chase, an officer reported that he thought he’d seen Williams with a gun. At the end, police mistook police gunfire for shots from Russell’s car.

Brelo fired 49 of those shots that night, but it was the final 15 fired into the windshield while he stood on the hood of Russell’s car that led to his indictment and a four-week trial. He faced up to 22 years in prison if convicted on both counts.

The shooting helped prompt an investigation by the U.S. Department of Justice that concluded Cleveland police had engaged in a pattern and practice of excessive use of force and violations of people’s civil rights.

Jackson said protesters were encouraged to continue expressing their opinions as long as they stayed peaceful. Williams said police only moved in Saturday when things got violent and people refused to disperse.

“We want to make sure that people understand we’re going to help you in this process but if things turn violent, as we stated in the beginning, we will take action to preserve safety in the city,” Williams said.

The protests erupted as authorities work to complete an investigation into the Tamir Rice shooting, the findings of which will be given to the prosecutor’s office to decide whether to pursue criminal charges.

Alicia Kirkman, 47, of Cleveland, said she joined the march in honor of her son, killed in a police shooting eight years ago.

“I’m just so mad we never get justice from any of the police killings,” said Kirkman, who said she settled with the city after her son’s death but no charges were filed.

The judge said in his ruling that he wouldn’t “sacrifice” Brelo to the wave of anti-police sentiment that has swept across the nation in the wake of other police in-custody deaths. While protests in cities like Baltimore, New York City and Ferguson, Missouri, have erupted into violence, the demonstrations in Cleveland didn’t escalate.

The judge’s decision to acquit Brelo focused on which shots killed Russell, 43, and Williams, 30, two homeless drug addicts with a long history of mental illness. Four of the 23 gunshot wounds to Russell and seven of Williams’ 24 wounds were believed to have been fatal. Judge John P. O’Donnell said in his 35-page verdict that while testimony showed Brelo fired some of the fatal shots, other officers fired kill shots as well.

A grand jury charged five police supervisors with misdemeanor dereliction of duty for failing to control the chase. All five have pleaded not guilty and no trial date has been set.

Prosecutors had argued that when Brelo stood on the hood of the Malibu that he meant to kill Russell and Williams instead of containing a threat to his and other officers’ lives. O’Donnell ruled that even the last 15 shots were justified based on Brelo’s belief that someone inside the car had fired at police at the beginning, middle and end of the chase.

“Officer Brelo risked his life on that night,” Brelo’s lead attorney, Patrick D’Angelo, said after the verdict.

Cuyahoga County Prosecutor Tim McGinty said he respected O’Donnell’s decision, and added that the case would prevent police violence.

In addition to the Tamir Rice case, the county prosecutor’s office is looking into the death of a black woman who died in police custody while lying face first on the ground in handcuffs. The family of Tanisha Anderson, 37, has sued the city of Cleveland and the two police officers who subdued her. They say she panicked Nov. 12 when officers put her in the back of a patrol car after they’d responded to a call about Anderson having a mental health crisis.

Russell’s sister, Michelle, said Brelo would ultimately face justice, despite the judge’s decision. The city of Cleveland has paid the families of Russell and Williams a total of $3 million to settle a federal civil rights lawsuit.

“He’s not going to dodge this just because he was acquitted,” Michelle Russell said. “God will have the final say.”

Associated Press writers Andrew Welsh-Huggins, John Seewer in Toledo and John Coyne contributed to this report.